It is common, where a large number of stored items are to be used often, that the items be organized in some manner to expedite the access to and use of the items. Examples are the storage of LPs in a radio station, the storage of commercials and programs in a radio or television station, or even the storage of music or videos in the home. The items must be organized well to be used effectively.
A common storage medium is a shelf, or a number of shelves. For example, the items can be stacked or lined up along a shelf (such as in a book case). Where the items are removed from and replaced on the shelf often, especially where more than one person is using the items, the items can easily become disorganized. The disorganization occurs because it takes time and effort to figure out where on the shelf the item is supposed to be replaced. This problem increases dramatically where the storage and organization of a large number of items is required.
For example, in the radio or television industry, hundreds of separate commercials and programs for each day of programming are stored on individual cassettes. Often, time constraints in these industries intensify the need for organization of the cassettes so that the proper programming can be selected for use at a moments notice.